Note 3 - Securities - Amortized Cost and Fair Values of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jun. 30, 2020
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 4,930
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	5,006
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	14,015
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	14,545
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	13,700
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	14,327
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	39,006
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	41,766
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	71,651
Available-for-sale Securities, Debt Maturities, Single Maturity Date	75,644
Available-for-sale securities, Amortized Cost Basis	139,932	$ 138,525
Total available-for-sale securities	145,665	143,918
Due after one year through five years, Net Carrying Amount	334
Due after one year through five years, Fair Value	356
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	667
Held-to-maturity Securities, Debt Maturities, Year Five Through Ten, Fair Value	735
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	2,335
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	2,514
Total held-to-maturity securities	3,336	3,541
Held-to-maturity Securities, Fair Value	3,605	$ 3,868
U.S. Government-sponsored Mortgage-backed and Related Securities [Member]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	69,281
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	$ 70,021